Symbolism is using one thing to stand for another thing — usually a concrete object standing for an idea you cannot see or touch. A dove for peace. A red rose for love. Black clothes for mourning. The word covers both the practice ('the symbolism in her paintings is heavy') and the collection of symbols themselves ('the symbolism of the imperial court').

You meet it most in three places. In talking about art and literature: what the writer meant by the storm in chapter nine, why the caged bird keeps coming back. In talking about religion and ritual: the symbolism of water in baptism, the symbolism of the colours in a temple. And in talking about politics and public life, where the meaning shifts slightly toward gesture — 'the visit was pure symbolism' means the leader went there to be seen and to make people feel something, not to change anything. That third use is often mildly critical: symbolism as opposed to substance, the sign of an action instead of the action.

There is also a capital-S use: Symbolism was a movement in French poetry and painting in the late 1800s — Mallarmé, Verlaine, Redon — which tried to suggest feelings through images rather than state them directly. If you meet 'the Symbolists' in an art book, that is what it means, and the movement is why English later borrowed some of the word's fancier flavour from French.

Though actually — a caution students almost never get told. Symbolism is one of those words that makes people over-read. In a classroom it is easy to decide that every object in a story must stand for something, and that the author planted it there on purpose. Sometimes yes. But writers also just need it to rain. Real symbolism usually announces itself by repeating, by getting more weight than the plot needs, or by fitting a pattern the culture already shares. One yellow curtain is a curtain.